I have a b18a1 with a built bottom end( not balanced though) and a stock head. My car is trapping a bit higher than i thought it would for my setup and i find myself revving the crap out of the engine before i get to the finish line.
I am running a ys1 transmission but it has gsr internals and a factory lsd. Slicks are 24.5" and im trapping 115 mph. At that rpm my datalog is showing 7300 rpm which is way out of my peak torque curve.
Im trying to get some advice on what to do on my setup to help fix this problem. THese are the ideas i have came up with:
put on a vtec head which will allow it to breath better up top. The problem is im not 100% sure my je srp pistons are vtec compatible. I will have to call je to confirm this.
2)take my stock head, which is freshly rebuilt and upgrade the valve train. Im not sure if its worth upgrading cams at the same time or if i should just to valvesprings, etc.
3)build an ls transmission with a quaife lsd. I dont particulary want to do this as i had just finished doing this hybrid transmission setup a few months back.
Heres a picture of my dyno plot. The higher torque/hp lines are the ones at 16 lbs, which is what i run at the track.
You can see that even at 6500 my torque and hp are falling like crazy. I would be scared to know how low they are at 7500. I tried shifting into 5th but that hurts the trap speeds a bit.
the only thing with the vtec head that im concerned about is the fact that i didnt balance my bottom end when i had it rebuilt. Not sure how high you can rev the ls bottom ends.
doh! For some reason i skipped right over yours, sorry about that. 20" slicks wouldnt cut it for traction and 26 inch would mean i would have to cut a lot of my fenders out. Not something i really want to do.
Right now im leaning towards the cheapest route which would be taking 3,4,5 from my ls transmission and mixing them with my gsr internals. That way i would still have a little better gearing then the ls gearbox as i would have the 4.4 final drive.
It would also mean that its the 3rd time ive had my transmission out of my car in as many months
I would jsut run a taller tire. That is way cheaper route. I run 225/45/27 tires on miens daily, that is a 25" tall tire. I’m trapping 124mph in 4th gear with a J1 tranny.
its pretty low. I had to cut the shit out of a spare set of fenders just to get the 24.5 inch slicks to fit. I plan on raising it up a bit when i get coilovers, but not too much.
if you are using spare fenders why would it matter if you cut them a bit? 402 cams are pretty weak. i may consider selling my built ls head with 404 cams pretty soon.
both of you guys are running 11s huh?
i dont think that bigger slicks is the best route at this time. 24.5 inch are plenty big for my hp numbers. I am running spare fenders right now because i havent had a chance to pickup some full coilovers and raise the car up enough to fit the slicks i have now.
I have read that cranes turbo cams are supposed to be even better than the crower cams so i may check out that option down the road as well.
